This sounds like something worth having around the shop! Can
you give us a source for the 'phos-copper' additive?
I use this as well in any alloys with a copper content as a
de-oxidiser. It’s the copper component that can be a propblem, as it
absorbs gasses during the melr and hangs onto them.
I call it Copper-Phos, and I get it from a local foundry here. I
first learned of its use from Phil Baldwin, who does all the bi-metals
and shakudo and shibuichi alloys on sale at Reactive Metals
Cu-Phos now comes in handy tiny pellets like tiny shot. I use about
0.5% added to the melt 20 - 30 seconds before pouring.
As it’s a great de-oxidieser I use a flame (oxy-propane) that is
deliberately more oxidising than normal. This heats the charge up
quicker, and after all I’m ‘de-oxidising’ aren’t I. The extra oxigen
prevents excess hydrogen in the flame (one won’t exist if the other is
there) and thence being absorbed in the metal, combining with ox in
the atmosphere and turning into H2O (steam) and causing blow-outs. To
quote someone before me (Gareth White) ‘The optimum amount of
phosphorous to use in casting is simple “just enough”.’
I don’t know of a supplier in your country.
B r i a n A d a m J e w e l l e r y E y e w e a r
@Brian_Adam1 ph/fx +64 9 817 6816 NEW ZEALAND
http://www.adam.co.nz/ photos from Australia!!
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